An aztec legacy to modern medicine

In 1519 the first Spanish expedition reached Mexico. Hernán Cortés and his soldiers found and advanced civilization with complex traditions and beliefs, with people who had developed a sophisticated form of writing together with a well developed calendar system and methods of counting. They found poets, statesmen, craftmen and in general extremely religious people, characteristic that importantly inspired their art, architecture, medicine and all aspects of their way of life.

The conquerors hunger for gold was only matched by their desire for winning converts to Catholicism. With the blessing of the church, it only took the conquerors a few years to destroy the entire civilization forcing the indians to adopt the "true faith". Despite this fact, the missionaries studied the indian language, "nahuatl", as well as the Indian customs and traditions. In this way the spiritual conquest was directly tied to the birth of the ethnographic studies in the New World. The encounter of the two completely different cultures produced in every aspect of life an interesting exchange of knowledge that nowadays is still difficult to understand and in many cases identify. During the 16th century when Spanish medicine extending all over Europe reaches its peak, the extraordinary discovery of the indigenous medicine was made. During this time, medicine in Europe was more interested in the understanding of the symptoms of the different illnesses and the obsession to eliminate them rather than to elaborate complicated diagnostic schemes. These were times of empiric observation that eventually would evolve to what we know as scientific medicine. Not only in Europe, but between arabs and chinnese as well, a great effort in medicine was employed to erradicate mankind from pain; and the common resource to achieve this goal was based on the treatment with herbs and plants. With great admiration, the first spanish explorers in the new world, found that medicinal herbs were also the great resource for the treatment of illness among American Indians.

Although, several detailed studies of the religious customs, ceremonies, and medical practices of the Indians were made at that time, it is still unknown how many of the original indian descriptions were destroyed. The most important of the descriptions made by the missionaries is unquestionably the work carried out by Fray Bernardino de Sahagún in a twelve volume treatise dictated in nahuatl by the indians themselves. This treatise was called "La Historia General de las Cosas de la Nueva España" which for ten years was patiently collected.2 From this information the Franciscan frair produced a complete history of the life and religion of the indians, which permited later scholars to reconstruct different aspects of Indian life, that otherwise would have been irremediably lost.

Not only the Catholic Church, but also the soldiers, the administrative officers of the newly established colony, and importantly the Spanish doctors, showed their admiration for the knowledge the Aztec doctors in their different classifications, educated ones and sorcerers, had accumulated throughout the years.3 Nowadays it is well known that pharmacology based in medicinal herbs was much more advanced among the Aztecs than in Europe. Aztec doctors going a step further, supported on their knowledge of medicinal properties of plants, classified them in groups based on their characteristics and basic properties. This classification considered more therapeutic than botanical has been considered original, scientific and in general so good to the extent that it has been compared to the one created by Caius Plinius Secundus (Plinio) much later in Europe.4,5 It is believed one of the main reasons for this advantage resides in the Royal Botanical Gardens Moctezuma I had built in Tenochtitlan and other settlements near the capital city like Oaxtepec. These botanical gardens were described by Cortéz as having at least a circunference of five miles with an enormus collection of different species containing from tall and old trees to small water plants, cacti, herbs, liquens, fungi, palm trees, etc; that could have contained at least two thousand different species. It is believed most species were accumulated through the years with specimes collected from different regions of Mexico and Central America by the practice of commerce with the northern regions of South America. It is important to point out that these Imperial Botanical Gardens were specially designed to preserve the rough materials employed by the "tepatle" to prepare medicinal formulae, and more importantly to encourage experimentation and investigation. While in these places this elite, mainly by using the method of assay and error, studied the plants thought to have medicinal properties, most markets in Tenochtitlan sold all kinds of materials employed as medicine.6

Bernal Díaz del Castillo, historian for excellence, confident in his prodigious memory, decades after the great events had taken place, wrote about his impressions of the market at Tlatelolco. He says, "As there are so many details to relate, we would never finish if we mentioned them all. Among these things are paper made from tree bark called "amat1", internodes of perfume, liquid amber, tobacco, yellow ointments, and many other things readily sold in the porticos of the plaza where herbs and other articles could also be found". Cooked produce, macerated material, dry powder, oil, etc; were the most common forms af administering drugs from plants which the Europeans greatly admired and which the Aztecs used to employ as laxatives, emetics, diuretics , antiemetics, and sudorific drugs, ocitocico abortifacients, parasiticides, antidiarrhea remedies, etc.6

The aztecs focused their attention to the different parts of the medicinal plants, specialy to the flower and fruit. This type of observation helped them to classify the different species according to the leaves "tlapalli" which differ in '"altapalli" if they came from a tree and "xiuhatlapalli" from the flowers. The petals were named "xochiallapalli" or "xochizuatl" the fruit "xochiqualli", the seeds "achtli", the medicinal root "tzocuilpatli", the wood "quauhuatzalli" and the bark "tlaxipeualli". From a general point of view it is evident that the aztec doctors at the begining of the 16th century were in a much better therapeutic position closer what it can be considered modern medicine than the european counterpart. This fact results to be extremely interesting since our modern medicine evolved primarily from Europe.

The therapeutic arsenal at the disposal of the aztec doctors was quite ample, consisting mainly of vegetal substances prepared and applied in different forms, together with different animal and mineral substances such as sulphur "tlaquiquztlalli" and lime "tenextle". Díaz del Castillo took great care in his writings mentioning the knowledge the Indian doctors had about the curative power of these substances.

Indians made use of infusions, poultices, concoctions, ointments and oils from materials like the ones found in Tlatelolco. From their oils, resins and balsams, the most common and best employed were the "tapatl" (Ricinus communis), the "chilli", the "ulli" or elastic resin and the "ocotl" containing tar and fir oil; some of them prepared by cooking and others by distillation.

Some examples of the substances contained in their preparations were: balsam, copal gum, liquid amber, sarsaparrilla , jalop, rhubarb of the frairs, hazel nut, michoacan, and many others which served and some of them still used as emetics "meijochitl and meijcotlapatli", antidotes for snake poison "coanepilli", remedies for the fever "chiantzollin", sneeze inductors "zozojatic" and cardioactive preparations from the flower called 'yoloxochitl' between others.

Surgery among the Aztecs achieved a high degree of development, perhaps because of the continual wars in which they were engaged with their territorial neighbors. Aztec physicians excelled in what we can call traumatic medicine. Bloodletting was also performed with skill using lancets "itztli" and with regard to surgery, the Spanish conquerors themselves assure from their own experience that wounds were cured with promptness and ease.

Unfortunately during and immediately after the conquest of Mexico, the Aztec codexes where most of the medical knowledge of several centuries was contained, were totally destroyed. Nowadays it is believed there are myriads of information still unknown to the modern world, first due to this destruction and second due to the oversight of merchants during colonial times. Nevertheless, some of this information reached Spain with the first accounts about Moctezuma’s botanical gardens and the skill by which the Aztec doctors employed a great number of medicinal plants cultivated in those gardens. So striking this information was to Phillip II and the Pope that they sent special envoys in order to learn as much as possible from the Mexican plants and their therapeutic use.

The manuscript known as the "La Cruz/Badiano" manuscript entitled "Libellus of Medicinalibus Indorum Herbis" written by Martín de La Cruz a "tepatiani" or pharmacist, and Juan Badiano an Indian apprentice who translated it from the nahuatl to the latin, was written in the College of Santa Cruz Tlatelolco in 1552. This manuscript beautifully describes in 118 pages the different medicinal herbs the indians used, together with their uses and different applications.7 Most probably non of the books written in the new world describing the newly discovery herbs and plants and there use in medicine were except of the european influence. Even the first known manuscript of the type completed by Martín de la Cruz and Juan Badiano presents obvious influence of Hipocratic thinking.

The manuscript entitled "Tratado Breve de Anathomía y Chirugía y de algunas enfermedades que más comúnmente suelen hacer en esta Nueva España" written by the frair Agustín Farfán, graduated in medicine from the University of Mexico in 1567, describes the practice of pharmacy, medicine and surgery among the Aztec people. This work edited by Antonio Ricardo was primarily published in Mexico City in 1579, and in 1592 reedited with the title "Tractado breve de medicina y de otras enfermedades". In 1610 it was again edited in Mexico by Geronymo Balli.

The treatise entitled "Historia Natural de la Nueva España" was written by the spanish physician Francisco Hernández, special envoy of Phillip II. This monumental treasure written 50 years after the conquest took place, is the most valuable piece of information we have from the medicinal plants the Aztecs used. Dr. Hernández worked with educated aztecs and spent seven years traveling from 1571 to 1577 before he went back to Spain with his indiscriptible set of drawings and his description of plants written 1n nahuatl, latin and spanish.8 From the three thousand different plants with medicinal properties he studied, finally he reduced the number to one thousand before his work was published by Reechi in 1628. It is important to note that since at that time the system devised by Linneo was still unknown, Dr. Hernández entirely followed in his study the classification system adopted by the indians.

Although the manuscript written by de la Cruz/Badiano remained unknown for a long time in the custody of the Catholic Church in Rome, soon after the manuscripts by Farfán and Hernández were published, several other studies on Aztec medicine and pharmacy came to light. One example is the manuscript written by Gregorio López in Oaxtepec between 1580 and 1589. The first publication of "Tesoro de Medicina" was carried out in 1672 in Mexico, after the death of the author.

In 1591 Juan de Cárdenas published in Mexico his book entitled "Primera parte de los problemas y secretos maravillosos de las Indias" and edited by Pedro Ocharte. The manuscript, divided in three sections, describes the characteristics of the metals, the plants, and the different products from the newly discovered land; as well as the qualities of men and animals born in the New Indies.9

Nicolás de Monardes, that never came to the American Continent, was always interested in the native medicine from the new Indies. In 1565 he published in Sevilla, Spain, his book "Historia medicinal de las cosas que se traen de nuestras Indias Occidentales que sirven en medicina". In this book the author discusses the medicinal properties of many herbs and plants like the "raíz de michoacán", tobacco, "carda santa" and others. Interestingly, this book has 27 editions in different languages.

The books above mentioned, a few medical references of contemporary studies and some additional information obtained from archeological findings constitute the main source of information we have about the use of herbs and plants in Aztec medicine.

Nowadays there are between 800,000 and 900,000 Indians who still speak the ancient Aztec language of nahuatl. They are the largest community of modern indians scattered throughout the country, where the only tide found between groups is their language.

Although modern medicine is being more accesible to the different nahua groups, as they are known today, they still make use of traditional medicine as a legacy of their predecessors.

Interestingly, as already described for the Aztec market of Tlatelolco, there is still possible to find special areas in most markets in modern Mexico City where all kind of plants and herbs are sold with the same purpose as already done several centuries ago.As it ocurred in the 16th century, following the tradition, many different preparations from these plants and herbs still have special curative properties not only for the nahua people but for many other groups in modern Mexico.

For more than a century, natural product research has been performed worldwide. However, in spite of the important investigation activity we have nowadays on the identification of new substances isolated from plants and herbs, the real potential has not been fully exploited.10 Taking into account the enormus amount of species still not studied, it is important to preserve for future generations of scientists areas like the tropical rain forests where most of these species grow, and by saving these areas from total destruction, to be able to fully decipher the great legacy our predecessors initiated.